Open-hearth furnace



May 27, 1-924. 1,495,725

A. CAMPBELL OPEN HEARTH FURNACE Filed Jan. 28, 1922 WM M Patented ay 27,1924.

if: T QF C ennrenw CAMPBELL, or NEWCASTLE, N EW sonrrn wri es, nusrnAtrA, nssIGNon TO THE BROKEN HILL rnorninrnn r correnn n @L iaI'rEn,noonronn'cfiron or man s'rA'rEor vroronm, A S RA I ornn-nnnnjrn rnnnncn.

Application filed January28, 1922. Seria1 No. 532,520.

To all whom it may concern:

Be it known that I, Annnnw CAMIBELL, a subject of the King of GreatBritain, residing at Maryville, Newcastle, New South Wales, Australia,have invented a new and useful Open-Hearth Furnace, of which thefollowing is a specification.

The invention relates to open hearth furnaces. The object is to provideimproved method and means for controlling the tern: perature of one ormore of the regenerators independently of the other regenerators, or atleast independently of the usual means for controllingthe temperature ofthe other regenerators, preferably the air regenerators independently ofthe gas regenerators.

The invention comprises the vmethod and means for increasing the draftthrough one of the regenerators relatively to that of anotherregenerator, or for controlling the draft so as to increase or decreasethe'pressure in the waste gases passingthrough one or more regeneratorsto the stack. This may be done conveniently by connecting an airregenerator directly with the stack, independently of, or in cooperationwith, the means for reversing the flow-betweentheregenerators and thestack.

Referring to the drawings which represent, merely by way of example,suitable means for effecting my invention Fig. 1 is a plan, in diagram,representing the gas regenerators and theairregenerators and the fluesand ports for connecting the same with the stack.

Fig. 2 is a diagram, insection indicating the valve control for theflues or passages.

Similar numerals indicate similar parts. in the difierent views.

The gas regenerators 1 and 2 are of the usual checker construction, asare likewise the air regenerators 3 and 4C. These regenerators have theusual connections-to the combustion ch amber or furnace, and the usualconnections and controls for the air and gas supply. Such connectionsand controls are not shown, because they may be in accord with thecommon practice and they form no part of the present invention. The airregenerators 3 and 4 .are connected to the fines ,or passages 7 and 8respectively. The flue or passage 9 leads directly to the stack 10. Thefines or passages 5 and 6 areprovided with the ports' ll and 12respectively. Thefluesorpassagesfi and 8 are provided with the ports 1.3and 1.4: respec ive y The flue .er passage .911 5 provided with the"ports 15 and 116. This fine or passage ;9 is also ;in open,comlnunication with the space orchamber 17. ml u ication between flue?.and fine 8 and chamber 17 is controlled by any suitable valves, such as1 8 and 19. Communication be wee p0rts-l3, 1.4 and-16am ports ,12 a d 15is c nt olledheusua way byany suitablefor n ofreversing valve, 81,191for ex.- ample, a he a e 20, actua ediby the p t 21, ope a g i cy nd 22-'Iti ommo n we knewn:prae ee-to p ov de mean for au om ic y nne ting hregen ra o po which is d sconnnected f om th ck por wit the .gas o ai upy, a he case may be. It is alseeom I mon practice to supplysuch furthercontrolli g a re may be esired- Such device ar not shown i t i presen,applieat en, since th y are assu d and ormn ipa 0f the presentinvention. i

This method of controlling, andreversing the direction of flow of airand gasithrou h h r gen r iv ch m ers, (by firs tablis ing com un c ti net nese of :fiue such as 5 and 7 and the stack, and theninterruptingsuch communication, and establ h ng commun i be ween he e her s offirms, such as 6 and 8, and the stackis common practice and wellunderstood inthe art. I Y

It happens however Y-that, at the beginning Thisundesirable conditionincreases -as the I run-progresses, and thus, under ordinary.circumstances, the efficiency of. regenerativeaction of the chamberbecomes impaired. It is therefore the practice that when theseregenerators become so clogged that theiefliciency of the furnace isreduced to such an extent that the cost of operation is excessive, thefurnace isallowed to. cool .down and the regenerators are clearedouteitherby steam or air jets, or by the removal of the checkers andcleaning of same by hand and replacement by new bricks Where necessary.

I have found that these extensive delays to furnace operations areovercome by a very simple and effective method, and the efiiciency ofthe furnace maintained without impairment as long as the roof of thefurnace lasts, or until extensive general repairs are requirednecessitating the cooling off of the furnace. This consists in providinga space such as chamber 17, or its equivalent, which, as above stated,is in free and open communication with the stack fine 9, and means forbypassing the flow from flue 7 or 8, independently of the usualreversing valve control of communication between the regenerator finesand the stack.

The communication between iiues T and 8 and chamber 17, which iscontrolled by any suitable form of valves, 18 and 19, is preferably aregulatable control. This permits of a flow from the air regeneratorflue to the stack entirely through chamber 17, or it may be inconjunction with the flow through the reversing valve or valves,controlling ports ll, 12 and 15, and 18, i l and 16. in this way as theair regenerator becomes more and more obstructed the eiiiciency ofcommunication between said regenerator and the stack may becorrespondingly increased or varied and thus the required heating of theregenerator may be secured under the varying conditions of the run. Andthe temperature of the air regenerator may be controlled independentlyof the temperature of the gas regenerator.

The valves or 18 and 19 may be urbitrarily operated, as for example, bymeans ofhand Wheels 18 and 19 as shown in Fig. 1, or they may also beprovided with suitable connecting mechanism so to secure any desiredrelative actuation with respect to the operation of the regeneratorreversing valve.

One of the reversing valves may be used to control the operation of thegates 18 and 19, providing direct connection to the stack for the airregenprators by many suitable mechanical devices. Fig. 2 shows in adiagrammatic Way the wel lrnown Schild rcversing valve 20. connected bythe rod 23. to operate a Walking beam or roclring lever 2d, attached tothe gates, providing direct connection to the stack for the air regenerators, and the lift of each gate valve is fixed by the position of anadjustable nut lit is obvious that the rod and lever in; placed. to suitconditions and to give the same motion as shown in the drawing. Such anarrangement gives the same throw to the gates at each reversal, and ifincreased or decreased pull through the air checkers is required, thismay be secured by changing the positions of the adjustable nuts.

In operation: It will be understood that the regenerators are connectedto the furnee/5,725

nace, in the usual Way, that is to say, the gas and air regenerators forexample 1 and 3 are connected to ports delivering to and from thefurnace chamber at one end or side thereof, while the air and gasregenerators t and 2 are similarly connected to ports at the other endor side of the furnace chamber. By the usual operation of the reversingvalves the two regenerators on one side of the furnace are connected tothe stee while the two regenerators on the other side of the furnace aredisconnected from the stack. The two regenerators, not connected Withthe stack, are connected respectively with air and gas supplies by meansnot shown, as such means form no part of the present invention.

Assuming, for example, that regenerators 1 and 3 are connected to thestack 1.0 by means of a reversing valve, such as 2.0, in Fig. 2, andthat the portslQ and l-l leading to regenerators 2 and are connected tosupplies of gas and air. we will have the usual operation as follows:The gas and air passing through the regenerators 2 and lreceive heattherefrom and are delivered to and through their respective ports in thefurnace. The combustible mixture thereby formed is burned within thefurnace chamber and the resulting burnt products pass through the portsat the other end of the furnace to and through the re enerators 1 and 3to the stack. This is the normal opera tion. In case however it shall bedesirable to increase the How of burnt products through a regenerator,in order to raise the temperature therein, it is possible, by thepresent invention, to control said flow inclependently of the reversingvalve and also independently of the other regenerator. For exampleassuming that it is desirable to increase the, flow of burnt productsfrom the furnace through regenerator 3 to the stack, it is onlynecessary to open valve 18 to secure a direct and unobstructed flow ofburnt products from the regenerator 3 to the stack, and this Will beindependent of the position of the reversing valve and also of the flowthrough regenerator 1..

What I claim is 1. In an open hearth furnace having the usualregenerators and reversing valve, the combination therewith of means forestab lishing, when required, a direct flow of burnt products from aregenerator to the stack independently of the reversing valve.

2. In an open hearth furnace, the combination of regenerators, areversing valve and means for establishing a by-pass be tween aregenerator and the stack and means for regulating said by-pass in orderto secure and maintain the required pres-- sure in said regenerator. i i

3. iln an open hearth furnace, the com-- binatlon of regenerators, areversing valve and means for establishing a bypass between aregenerator and the stack, means for regulating said by-pass and meansfor main taining a constant relationship between the reversing valve andthe regulating means.

4. In an open hearth furnace, the combination with regenerators and theusual reversing valve control of the regenerators, of means forcontrolling the flow from a regenerator to the stack eitherindependently of or in conjunction with the reversing valve control.

5. In an open hearth furnace, the combination with the regenerators andthe usual reversing valve control of the regenerators, of means forestablishing a separate flow from a regenerator to the stack inconjunction with the reversing valve control.

6. In an open hearth furnace, the combination with regenerators and theusual reversing valve control of the regenerators, of means forestablishinga by-pass flow from a regenerator to the stack in order tomodify the reversing valve control.

7. In an open hearth furnace, in combination with regenerators and theusual reversing valve control of the regenerators, means forming aby-pass communication between a regenerator and the stack and a controltherefor, adapted to operate relatively to the reversing valveoperation.

8. In an open hearth furnace, in combination with regenerators and theusual reversing valve control of the regenerators, means forming acontrolling by-pass communication between a regenerator and the stackadapted to operate either independently of or in cooperation with thereversing valve operation.

ANDREW CAMPBELL.

